Question

Study the four statements (A-D) given below and select the two correct ones out of them. The two correct statements are:
A. Biological species concept was given by Ernst Mayr.
B. Photoperiod does not affect reproduction in plants.
C. Binomial nomenclature system was given by R. H. Whittaker.
D. In unicellular organisms, reproduction is synonymous with growth.

1. A and D
2. A and B
3. B and C
4. C and D

Answer 1

Hint: The biological species concept was given by Ernst Mayr as it groups the members of the same species organisms which can interbreed with each other to produce fertile offspring. Photoperiod is referred to as the relative length of day to night.

Complete answer:
The biological species concept was given by Ernst Mayr which states that the members of the same species can interbreed with each other in order to produce fertile offspring. This concept helps us to understand the organisms which can have intercourse to give birth to life as if there is an inbreed between unrelated species then it will not lead to the new fertile offspring.
Photoperiod is the relative length of the day compared to the night which is used in flowering and flowers are the organs of sexual reproduction in the plants. This photoperiod helps the plant in the process of photosynthesis where they can make their own food. Photoperiod thus affects the reproduction in the plants.
Binomial nomenclature was given by Linnaeus, not by R. H. Whittaker. Linnaeus is considered the father of taxonomy and he was the first one to use binomial nomenclature for organisms. In unicellular organisms, reproduction is synonymous with growth as they reproduce to form other unicellular offspring and result in the growth of an organism.

Hence, the correct option is 1. A and D.

Note:
Unicellular organisms cannot become multicellular after cell division. They perform cell division to give rise to a new cell that divides from the parent cell and gets separated to become an individual. This division is common in various unicellular organisms.